It has conventionally been known that if carbon dioxide (carbonic acid anhydride: CO2) contacts the skin and the mucous membrane of the living organism, it penetrates into them only thereby, and it expands blood vessels around the parts of penetrated carbon dioxide and works to improve the blood circulation. Owing to this action of accelerating the blood circulation, carbon dioxide displays various physiological effects such as dropping of blood pressure, improving of metabolism or accelerating to remove pain substance or waste products. Further, it has also anti-inflammation and anti-bacterial. Therefore, carbon dioxide has recently been given attentions also from viewpoints of improving health or beauty other than the purpose of medical cares.
Carbon dioxide in the tissue of the living organism works to release oxygen having been carried in combination with hemoglobin in a red blood cell. Around parts at a high density of carbon dioxide, the red blood cell releases more oxygen. Thus, supply of oxygen to cells by the red blood cell is mainly controlled by carbon dioxide. In short, being without carbon dioxide, hemoglobin remains as having been combined with oxygen and the cell becomes unable to receive oxygen. As is seen, carbon dioxide seems to be a waste product resulted from action of the cell, however, it plays in fact very important roles in the living organism.
Further, in recent times, oxygen of the high density has also widely been known as effective in activity of metabolism, fatigue recovery, or stability of blood pressure. Other than them, oxygen has also effects of disinfection or sterilization by oxidation.
By the way, for easing a symptom of disease in a respiratory system such as asthma or allergic rhinitis, an oral inhalation or nasogastric inhalation using an inhaler or rhinenchysis spray have been till now operated.
Recently, a nasogastric vaccine (spray type nose vaccine) for forming a mucous membrane immunity to influenza virus has been developed and its high effect has been given attention. This nasogastric vaccine is higher in the effect preventing an influenza crisis than a vaccine of a hypodermic injection, and being different from an injection type, it has merits working effectively to various virus roots. Also in prevention or curing against influenza, antiviral drugs by an inhalation dosage have been developed.